Protection valve device



March 22, 1949. E G ERSON PROTECTION VALVE DEVICE Filed July 10, 1946INVENTOR Patented Mar. 22, 1949 PROTECTION VALVE DEVICE Erik G. Erson,Wilkinsburg, Pa., assignor to The Westinghouse Air Brake Company,Wilmerding, Pa., a corporation of' Pennsylvania Application July 10,1946, Serial No. 682,680

Claims. (Cl. 303-84) This invention relates to uid pres-sure brakes, andmore particularly to an air brake equipment of the type employed on arailway locomotive.

Diesel-powered locomotives for certain classes of railway service insome instances comprise a plurality of individual power units coupledtogether. For example, a complete Diesel locomotive may consist of one A(control) unit coupled to first and -second B (auxiliary) units, allthree power units carrying engine equipments controlled from the A unit.Diesel locomotives of this class are operative to exert great tractiveeort, particularly at low speeds. such Diesel locomotives are regularlyoperated to great advantage and without undue risk of separation of theseveral units, actual experience has demonstrated that such an accidentis possible, and that the leading portion of a Diesel locomo tive mightbreak away from the other units an-d the rest of the train. The engineerstationed in the leading portion may in fact be unaware that abreak-in-two has occurred, by reason of the enormous power which thatunit delivers, and as a result, the parting of the main reservoir pipebetween the separated units of the locomotive may seriously impair hiscontrol of the brake equipment. The locomotive brake equipment on amultiple unit Diesel locomotive is, of cour-se, designed to operateautomatically upon parting of the brake pipe to effect an emergencyapplication of the brakes, but if the engineer is unaware of abreak-in-two and consequently allows his brake valve to remain inrunning position, and if, as is usually the case, the controlledemergen-cy feature of the equipment has been set for freight service topermit only a slow rate oi brake cylinder pressure development, the lossof main reservoir pressure through the broken main reservoir pipe willin a short time seriously limit the brake cylinder/pressure obtainablein the leading portion of the locomotive.

It is an object of my invention to provide an improved locomotive brakeequipment designed for Diesel units of the above identied class,including means operative to prevent brake failures of this nature.

Another object of the invention is to provide an improved protectionvalve device operative to prevent complete loss of main reservoirpressure in the leading locomotive in case of a train break-in-two.

A further object is to provide improved means operative to permit the owof fluid under pressure from a main reservoir on the first locomotiveunit through the main reservoir pipe to the Although reservoir on thetrailing locomotive unit only after the fluid under pressure in thereservoir of the rst locomotive unit attains a selected degree ofpressure and operative thereafter when the fluid vpressure in the mainreservoir pipe is reduced to a chosen lower degree to prevent the flowof fluid un-der pressure from the reservoirs on the rst unit to the mainreservoir pipe, whlch means may be readily installed in an existingbrake equipment for cooperation with standard brake controlling deviceswithout impairing the normal functioning of the apparatus. A

This invention will be described as embodied with a locomotive freightequipment, and constitutes an improvement in that part of the equipmentwhich form the subject matter of patent application by Glenn T. McClure,Serial No. 582,934, led March 15, 1945 and assigned to the assignee ofthe present invention, which issued September 1'7, 1946 as Patent No.2,407,890.

Other objects and advantages will be apparent in the following moredetailed description of the invention. l

The single gure in the accompanying drawing is a diagrammatic view,partly in section, of a protection valve device constructed in accord`ance with the invention and associated with such portions of the airbrake equipment of a multiple unit Diesel locomotive as concern theinvention,

In the drawing, the reference numerals l and 2 indicate a pair of mainreservoirs which are carried on the leading locomotive unit andcornprise a part of the usual air brake equipment (not shown) thereon.The main reservoirs I and 2 are connected by means of a' pipe 3 tc apre1 tection valve device 4, which device operatesto controlcommunication between the pine 3 and a main reservoir pipe 5, as willhereinafter more fully appear. A check valve device 6 is provided toprevent back now of duid under pressure from the main reservoir 2 to thepipe 3, the main refervoir 2 being provided for the purpose of storinguid under pressure to be supplied tol a pipe .l leading to the usual airbrake equipment (not shown) installed on the leading unit of a Die-sellocomotive. The main reservoir pipe 5 comprises a section 8, carried onthe leading locomotive unit. and a section 9 carried on the trailinglocomotive unit, sections 8 and 9 being connected by a coupling meansl0. The section 9 is'conneeted to a main reservoir Il which comprises apart of the usual air brake equipment (not shown) for the trailinglocomotive unit. It will be understood that the main ,reservoirs I and 2are adapted to be charged with iluid under pressure delivered by way ofa pipe I2 leading from a compressor (not shown) mounted on the leadinglocomotive unit, and the main reservoir II is adapted to be charged withiluid under pressure from a suitable compressor (not shown) mounted onthe trailing locomotive unit.

The protection valve device 4 may comprise a base structure I3supporting a ca-sing structure I4 and containing a supply chamber I5,which chamber is in constant open communication with the main reservoirI by way of the pipe 3. Contained in the supply chamber I5 is a supplycontrol valve I6, which valve cooperates with a valve seat I'I, formedon the end of a bushing I8, to control communication by way of saidbushing between the supply chamber I5 and a passage I 9, which passageconnects with the main reservoir pipe 8.

Formed in the casing structure I4 is a strainer and check valve chamber20, which chamber is in constant open communication with the supplychamber I5 by way of a passage 2l' and with a diaphragm chamber 23 byway of a passage 22. For the protection of the passage 22 against thepassing of dirt therethrough there is provided in chamber 2D a wirescreen strainer 24 which is clamped between two sections of the casingstructure I4. Also contained in the chamber 29 is a ball check valve 25arranged for operative engagement with a valve seat |26 formed in asuitable bushing 21 mounted in the casing structure I4, the under sideof the check valve 25 being in communication with the passage I9 by wayof a passage 28 and a chamber 29. For the protection of the valve device4 and the other air brake equipment when fluid under pressure from themain reservoir pipe 5 ows past the check valve 25, as will hereinaftermore fully appear, a tubular air cleaner or strainer 30 of the cartridgetype is mounted in the chamber 29 so as to have its inner periphery opento the passage 28 and outer periphery exposed to the passage I9. Uponremoval of a cap nut 3| which closes the outer end of the chamber 29 andhas sealing engagement with one end of the strainer 30, the strainer maybe readily removed for cleaning.

Clamped at its periphery between two sections of the casing structure I4is a flexible diaphragm 32 having at its lower side a spring chamber 33which is constantly open to atmosphere by way of a passage 34. while atthe upper side of the diaphragm 32 there is the chamber 23 which isalways connected with passage 22 as previously noted and is alsoconnected to the interior of a bushing 35 by way of the passage 22 and apassage 36. At the lower end of the bushing 35 is a spring chamber 31which is ln constant open communication with the atmosphere by way of apassage 38 and a choke 39, and at the upper end of the bushing isanother spring chamber 40 which is open to a passage 4-I leading to apiston chamber 42. For controlling communication between the springchambers 31 and 40 and between the passage 36 and the chamber 40, avalve member 43 is slidably mounted in the bushing 35. The upper end ofthe valve member 43 is provided with a conical valve 44 for sealingengagementl with the upper end of the bushing 35, and the lower end ofthe valve member is provided with an annular valve seat 45 forcooperation with an exhaust valve 46 contained in the spring chamber 31and slidably guided by means of a fluted stem in a through axial bore 41in said valve member. Engaging the diaphragm 23 and extending through asuitably sealed bore from the chamber 37 to the chamber 23 is a stem 48for eiecting an operative connection between the diaphragm and the valvemember 43. Interposed between and operatively engaging the stem 48 andthe bottom of the bushing 35 is a spring 49 which tends at all times tokeep the stem in abutting engagement with the diaphragm 32. Interposedbetween a cap nut 50 closing the top of the chamber 37 and the valvemember 43 is a spring 5I' which tends at all times to move the valvemember downwardly toward the position in which it is shown.

Contained in the chamber 33 and interposed between a diaphragm followermember 52 and a spring seat member 53 is a compression spring 54, which,as will hereinafter more fully appear, serves to establish the degreesof uid pressure in the supply chamber I5 at which the valve I8 will beopen or closed. The follower 52 is slidably guided in an annular member55, the member 55 also serving as a medium for clamping the diaphragm 32and being arranged in the chamber 33 so as to coniine the travel of thefollower 52 between a surface 56 of the member 55 and a shoulder 51provided in the peripheral wall of the chamber 33 as shown in thedrawing.

The spring seat member 53 slidably engages a stud portion 58 of thefollower member 52 for the purpose of retaining the spring 54 inoperative engagement with the follower member 52 and also for limiting,in a manner to be explained later, the upward travel of a piston member59 mounted in the chamber 42. The member 53 is substantially tubular inshape, having its upper end 69 turned inwardly for engagement with awasher 6I secured to the stud portion 58, and having its lower end 62flared outwardly for supporting and retaining the spring 54 at its lowerend and thereby caglng the spring.

The piston member 59 is substantially cupshaped for accommodating thelower ends of the spring 54 and the seat member 53 and abuts the bottomsurface of the seat member for pro pelling the same upwardly until theupper end 60 thereof engages the follower member 52. A sealing ring 63is provided in an annular groove in the periphery of piston member 59for preventing leakage of fluid under pressure from the chamber 42 tothe atmospheric chamber 33. The piston member 59 is further providedwith a downwardly extending stem 64 which is slidably mounted in athrough bushing 65 in a wall in the casing structure I4 and extendstransversely through the passage I9 and bushing I8 into the supplypassage I5. The stem 64 is also provided with a sealing ring 66 forpreventing leakage of uid under pressure between the passage I9 and thechamber 42. Secured by means of a pin 61 and a retaining spring or clip68 to the lower end of the stem 64 of the piston member 59 is the valveI'B, which, as will later appear, may be operated thereby intoengagement with the valve seat I 1. It is preferred that the clearancesin the mounting means of the valve I6 be suflicient to permit the valveto be self-aligning in its operation.

In charging the locomotive fluid pressure system with fluid underpressure, under normal conditions, fluid under pressure is suppliedfromthe usual compressor (not shown) on the leading locomotive to themain reservoir I by way of the pipe I2 and flows therefrom by way' ofthe pipe 3, check valve device 6, and a pipe 69 to the main v23 hasattained a higher 100 pounds, the diaphragm 32 will deiiectdownspondingly increased.

'- gagement reservoir 2, from which fluid under pressure is supplied byway of pipe 1 to the usual air brake control equipment on the leadingunit lof a Diesel locomotive. Fluid under pressure also flows from pipe3 through a passage 10 to the supply chamber I5 of the protection valvedevice 4. At the same time fluid under pressure is also supplied to themain reservoir I I on the trailing unit by the operation of auxiliarycompressor means (not shown) mounted on that unit.

Fluid under pressure supplied to the chamber I5 of the protection valvedevice 4 flows from that chamber by way of the passage 2I to the chamber20, thence by way of a choke 1I inserted in the passage 22 for reasonswhich will appear later, .and from the passage 22 to the diaphragmchamber 23, whence it will flow by way of the passage 36, a cavity 'I2in the valve member 43, past the valve 44, which is unseated at thistime, to the chamber 49, and then to the piston chamber 42 by way of thepassage 4I. With the valve 46 seated, communication of the pistonchamber 42 to atmosphere is cut oli. The valve I6 being unseated asshown, iiuid under pressure in chamber I5 may also flow to the mainreservoir II by way of the bushing I8, chamber I9 and main reservoirpipe 5, if the uid pressure in the main reservoir II is lower, such aswhen the compressor (not shown) on the trailing unit is not operating.

Since the degree of fluid pressure in the chambers 23 and 42 issubstantially the same and the effective area of the piston member 59 isgreater than that of the diaphragm 32, the piston member 59 will respondto a lower degree of fluid pressure than will the diaphragm 32. When thepressure of iiuid in the chamber 42, has reached a chosen degree (22pounds for example) as determined by the value of the spring 54, thepiston member 59 will move the spring seat member 53 upwardly againstthe opposing pressure of the spring 54 until the valve I6 engages thevalve seat I1. With this movement the piston member 59 acts through themedium of its stem 64 and the pin 61 to move the valve I6 into sealingengagement with the valve seat I1, closing communication between thechambers I5 and I9 and thus between main reservoirs I and II.

However, uid under pressure will continue to iiow from chamber I5 tochambers 23 and 42 by way of the route previously described. When thepressure of iiuid in the diaphragm chamber chosen degree, such as wardlyin response thereto, causing the follower 52 to move downwardly untilstopped by engagement of the lower outer surface thereof with theshoulder 51 in the chamber 33. It will be noted that the spring 54 hadpreviously been compressed a certain amount due to the upward movementof the piston member 59, consequently the force of the spring acting tooppose the downward deiiection of the diaphragm was corre- Upondeflection of the diaphragm member toward its lower position, the spring5I will act to move the valve 44 of the valve member 43 downwardly intosealing engagement with the 4upper end oi the bushing 35, therebyclosing communication between the chambers `23 and 42.

"Further deflection of the diaphragm 32 toward its lower position willcause the spring 49 to actuate the valve 46 downwardly out of sealingenwith the valve seat 45 of the valve member 43 to the position in whichit is shown.

thus connecting chamber 42 to atmosphere.`

Fluid under pressure in chamber 42 will ilow by way of the passage 4I tochamber 40, thence through bore 41 of the valve member 43 and past valve46 to chamber 31, whence it will flow to atmosphere by way of thepassage 38 and choke 39. When the pressure of fluid in the chamber 42acting on the lower side of the piston member 59 devcreases below thepressure of the spring 54 acting on the upper side of the piston member,the spring will act to move the piston member downwardly to the positionin which it is shown in the drawing. The downward movement of the pistonmember will cause the valve I6 to assume the position in which it isshown, this being the nor' 3, passage 16, chamber I5, bushing I8,passage I9 and the main reservoir pipe 5.

, The positions in which the valve member 43 and the valve 49 are shownin the drawing are the normal positions for these valves on a leadingunit with the brake equipment thereof fully charged. It should benoted'that under these normal or prevailing conditions the communicationto atmosphere by way of the passage 38 and the choke 39 is cut ofi andthat in no case, even when charging, can the main reservoir pipe 5 beconnected to said passage and choke. Consequently there will be nosustained iiow of i'luid under pressure from the main reservoir pipe 5to atmosphere. The only time there will be any flow to atmosphere willbe that time subsequent to the operation to render the piston member 62and the valve I6 effective, and then only in a small measured amount.

It will be understood that the volume of the chamber 49, passage 4I andchamber 42 is relatively small and that consequently the choke 39,although of small flow capacity, will permit the uid pressure therein tobe rapidly depleted. It will be apparent therefor that substantially thefull force of the spring'll will be effective at once to open the valveI9 promptly. It should be further explained that any temporary liuidpressure drop in the chamber I5 which might be caused by the suddenopening o the valve I6, especially .fith the high pressure differentialacross it, will not, due to the flow restricting choke 1I, result in acorresponding reduction in the pressure of fluid in the diaphragmchamber 23, thus insuring against an undesirable operation of thediaphragm 32 and the piston'member 59 to again close the valve I6. Thusthe choke 1I serves to stabilize the diaphragm so that communicationfrom the main reservoir I tc the piston chamber 42 is maintained closedand the communication `from main reservoir I to the main reservoir I Iis maintained open against accidental movement.

If, however, the main reservoir line 5 is broken or opened to theatmosphere asby the accidental separation of the locomotive units, fluidunder pressure in the main reservoir I will flow to atmosphere by Way ofpipe 3, protection valve device 4, and the undesired rupture of the mainreservoir pipe 5. The resulting reduction in the fluid pressure inchamber I5 of the valve device 4 will cause uid under pressure to flowfrom the diaphragm chamber 23 by way of the passage 22, choke 1l,chamber 29 and passage 2l to chamber I5 and thence to atmosphere by wayof bushing I8, passage I9 and main reservoir pipe 5. When pressure offluid in chamber 23 has been reduced to some chosen low degree such as80 pounds, the predominant pressure of the spring 54 will cause thediaphragm 32 to deflect upwardly and act through the medium of the stem48 to move the valve 48 against the lesser opposing pressure of thespring i9 to its seated position, thereby closing communication ofchamber 42 to atmosphere, and then to actuate the valve 44 against thehigher opposing pressure of the spring I to its unseated position,thereby connecting chamber 23 to chamber 42.

With the valve 44 unseated, fluid under pressure in diaphragm chamber23, and consequently fluid under pressure in chamber I5 connected tochamber 23 by Way of the passage 2l, chamber 20, choke and passage 22,will ow to the piston chamber 42 by way of the passage 3B, cavity 12,chamber 4d and passage 4I. In response to the uid pressure acting on thepiston member 59, the piston member will move upwardly against theopposing pressure of the spring 54. This movement of the piston memberwill cause the valve i6 to again engage the valve seat I '1, thuspreventing further loss of fluid under pressure from the main reservoirI by way of pipe 5.

The reduction in the pressure of fluid in the main reservoir I willcause the compressor on the leading locomotive unit to start operatingin the usual manner. This action in combination with the closing of thevalve I5 might, if the choke 'il were not employed cause a rapidincrease in the fluid pressure in the diaphragm chamber 23 causing thevalve 46 to unseat and the valve 44 to seat before the fault causing theloss of uid under pressure had been corrected. There would then followanother reduction in iiuid pressure and a consequent rapid pumpingaction. This rapid pumping action is obviated by the eifect of the choke'H in the passage 22 which delays the pressure build-up in the chamber23 and thereby lengtliens the time interval between the closing andopening of the valve I6.

Assuming now that the compressor means on the leading locomotive unithas been rendered inoperative and that the compressor means on atrailing unit is operating to supply fluid under pressure to the mainreservoir II, the various parts of the protection valve device 4 will bein the position in which they are shown in the drawing. Fluid underpressure in the main reservoir II will flow therefrom to the mainreservoir I by way of the main reservoir` pipe 5, passage I8, bushingIS, chamber I5, passage 'ID and pipe 3 until the exemplary 22 pounds arereached, at which time the valve I6 will be operated to its seatedposition in the same manner as hereinbefore described for 22 pounds ofmain reservoir pressure during the initial charging of the locomotive.

However, although the iiow of fiuid under pressure above 22 pounds fromthe main reservoir II to the main reservoir I is interrupted at valveI6, this flow will continue from passage I9, and reservoir I I, by wayof strainer 30 in chamber 29, passage 28, past check valve 25, chamber20, passage 2|, chamber I5, passage 10 and pipe 3. When a fluid pressureof 100 pounds is attained in the main reservoir I and chamber 23 of theprotection valve device 4, the same operation for unseating the valve I6 will take place as previously described in connection with the initialcharging of the locomotive.

Having now described my invention whatI I claim as new and desire tosecure by Letters Patent is:

1. The combination with a fluid conducting conduit normally charged withuid under pressure, of a valve device comprising a casing having twocommunicating passages constituting a portion of said conduit, a valveoperative to open and close the communication between said passages.movable abtument means normally retaining said valve in its openposition and operative in response to uid pressure to close said valve,and valve means for controlling the supply of iiuid under pressure toand release of fluid under pressure from said movable abutment means,said valve means normally connecting said movable abutment means toatmosphere and being responsive to a certain degree of reduction influid pressure in one of said passages from the chosen normal pressureto close the connection of said movable abutment means to atmosphere andto connect said movable abutment means to said one passage.

2. In a fluid pressure flow control valve device having two connectedpassages adapted to establish communication between two fluid conductingconduits, a valve operative to one po sition to close the connectionbetween said passages and operative to another position for opening theconnection between said passages, piston means operative by iiuid underpressure from one of said passages for actuating said valve to close theconnection between said passages and operative upon a reduction in thepressure of such fluid for actuating said valve to open the connectionbetween said passages, valve means responsive to variations in thepressure of fluid in said one passage for controlling the pressure offluid acting on the first mentioned means, said valve means having anormal position in which said piston means is connected to atmosphereand being operative to another position in which the atmosphericconnection is closed and said piston means is connected to said onepassage, and a movable member responsive to variations in the pressureof uid in said one passage to operate said valve means.

3. In a fluid pressure flow control valve device having two connectedpassages adapted to establish communication between two iiuid conducting conduits, a valve operative to one position to close theconnection between said passages and operative to another position foropening the connection between said passages, piston means operative byfluid under pressure from one of said passages for actuating said valveto close the connection between said passages and operative upon areduction in the pressure of such iiuid for actuating said valve to openthe connection between said passages, valve means responsive tovariations in the pressure of fluid in said one passage for controllingthe pressure of fluid acting on the first mentioned means, said valvemeans having a normal position in which said piston means is connectedto atmosphere and being operative to another position in which theatmospheric connection is closed and said piston means is connected tosaid one` passage, and a movable member responsive to a reduction in thepressure of fluid in said one passage to actuate said valve means out ofsaid normal position to said other position.

4. The combination with a iiuid conducting conduit, of a uid pressureflow control valve de vice comprising a casing having two fluid ilowconnecting passages constituting a portion of said conduit, a valveoperable to open and close the uid flow connection between saidpassages, movable abutment means responsive to fluid pressure foroperating said valve to close said connection and responsive to areduction in fluid pressure for operating said valve to open saidconnection, and valve means operative to supply uid under pressure fromsaid one of said passages to the movable abutment means to eiect theoperation to close said valve and operative in response to a certaindegree of uid pressure acting thereon to interrupt said supply and toconnect said movable abutment means to atmosphere, thereby eiecting theoperation of said valve to open said uid flow connection, said valvemeans being conditioned as an incident to the opening of said valve torespond to a degree of fluid pressure acting thereon lower than saidcertain degree to close the atmospheric connection to said movableabutment means and to again supply fluid under pressure from said onepassage to said movable abutment means.

5. In combination, two fluid conducting passages, a valve controllingcommunication between said passages, piston means operable by fluidunder pressure for closing said valve, valve means controlled by thepressure of fluid in one of said passages and operable when suchpressure exceeds a chosen degree to release operating fluid underpressure from said piston means and when of a chosen lower value tosupply operating uid under pressure to said piston means, and means foropening said valve upon release of operating fluid under pressure fromsaid piston means.

ERIK G. ERSON.

REFERENCES CITED The following references are of record in the iile ofthis patent:

UNITED STATES PATENTS Number Name Date 1,469,585 McCune Oct. 2, 19232,407,890 McClure Sept. 17, 1946

